openstack-manuals/doc/admin-guide/source/image-authentication.rst

Authentication With keystone

Glance may optionally be integrated with the Identity service (keystone). When setting this up remember the keystone distribution includes the necessary middleware. Once you have installed keystone and edited your configuration files, newly created images will have their owner attribute set to the tenant of the authenticated users, and the is_public attribute will cause access to those images for which it is false to be restricted to only the owner, users with admin context, or tenants and users with whom the image has been shared.

Configuring the glance servers to use keystone

Keystone is integrated with glance through the use of middleware. The default configuration files for both the glance API and the glance registry use a single piece of middleware called unauthenticated-context. This generates a request context containing blank authentication information. In order to configure glance to use keystone, the authtoken and context middlewares must be deployed in place of the unauthenticated-context middleware. The authtoken middleware performs the authentication token validation and retrieves actual user authentication information. This can be found in the keystone distribution.

Configuring the glance API to use keystone

To configure the glance API to use keystone, ensure that declarations for the two pieces of middleware exist in the glance-api-paste.ini. For example:

[filter:authtoken]
paste.filter_factory = keystonemiddleware.auth_token:filter_factory
auth_url = http://localhost:35357
project_domain_id = default
project_name = service_admins
user_domain_id = default
username = glance_admin
password = password1234

The values for these variables will need to be set depending on your situation. For more information, please refer to the keystone documentation on the auth_token middleware.

• The auth_url variable points to the keystone service. This information is used by the middleware to query keystone about the validity of the authentication tokens.
• Use the auth credentials (project_name, project_domain_id, user_domain_id, username, and password) to retrieve a service token. That token will be used to authorize user tokens behind the scenes.

To enable using keystone authentication, the application pipeline must be modified. By default, it looks like:

[pipeline:glance-api]
pipeline = versionnegotiation unauthenticated-context apiv1app

Your particular pipeline may vary depending on other options, such as the image cache. This must be changed by replacing unauthenticated-context with authtoken and context:

[pipeline:glance-api]
pipeline = versionnegotiation authtoken context apiv1app

Configuring the glance registry to use keystone

To configure the glance registry to use keystone, the same middleware needs to be added to glance-registry-paste.ini as was needed by glance API. See above for an example of the authtoken configuration.

To enable using keystone authentication, the appropriate application pipeline must be selected. By default, it looks like:

[pipeline:glance-registry-keystone]
pipeline = authtoken context registryapp

To enable the above application pipeline, in your main glance-registry.conf configuration file, select the appropriate deployment flavor by adding a flavor attribute in the paste_deploy group:

[paste_deploy]
flavor = keystone

Note

If your authentication service uses a role other than admin to identify which users should be granted admin-level privileges, you must define it in the admin_role config attribute in both glance-registry.conf and glance-api.conf.